Discover the cause of disease. In the 18th century bacterial diseases were still a deadly mystery. Bacteria were sometimes found in diseased humans and animals — but did the bacteria cause the disease or did the bacteria merely follow a disease caused by another unknown agent? To know the cause is the first step toward cure or prevention. Join Robert Koch, Louis Pasteur, and the founders of modern microbiology in a thrilling search to find the bacterial culprit behind a new disease. The new disease examined in this lab is "yogurtness" — an affliction of "healthy" milk that causes it to become acidic and thick. What is the cause of yogurtness? Can you use Koch's postulates, the standard of proof in the identification of microbial disease agents, to identify the guilty microbe in this inquiry based activity?

Microbes and Health: "What Causes Yogurtness?"™ Kit

This PowerPoint presentation is intended for educational use only. The presentation provides educators with background on the Microbes and Health: "What Causes Yogurtness?" Kit and includes instructions for using the kit.

The Microbes and Health Kit allows you to set up a scenario in which students get to discover the cause of a new disease called "Yogurtness" — an affliction of "healthy" milk that causes it to become acidic and thick. What causes Yogurtness?™ Your students join Robert Koch, Louis Pasteur, and the founders of modern microbiology in a thrilling search to find the bacterial culprit behind this new disease. Using microscopes, agar plates, and their powers of observation, students identify the bacteria used to produce yogurt.

Features and Benefits

The chemistry of the bacterial cell is brought into focus in this inquiry-based laboratory kit as students examine bacteria and their interaction with the environment. With this kit students:

Examine metabolism, cellular chemistry, and the role of bacteria in both disease and food microbiology

Follow Koch's postulates to identify the causative agent for disease

Isolate and culture yogurt-causing bacteria

Learn microbiology skills and sterile technique

This kit is appropriate for biology, microbiology, health sciences, and biotechnology classes, or can be used for independent study.

Background Information

Enzyme-catalyzed chemical reactions in bacteria provide energy for the bacteria as they change food into secreted waste products. In some cases, bacterial waste products create foods and nutrients for people; in other cases they cause disease. For a long time, biotechnology has utilized friendly bacteria in the production of foods such as cheese, sauerkraut, kimchi, coffee, sour cream, vinegar, sausage, and yogurt. Other bacteria cause cholera, typhus, leprosy, tuberculosis, and anthrax. In this laboratory activity, students examine both the risks and benefits of bacteria to better understand their role in disease and food production.

More Information

Three–session laboratory activity, 45 min per session

Provides sufficient materials for eight student workstations, up to four students per workstation

For more than 15 years, Bio-Rad has made science education a major priority. To support
this effort, the company has implemented a discount policy that allows high school
and college teaching laboratories to purchase kits, instruments, reagents, and other
equipment at preferred prices.

How do I apply for the education discount?

If you are an educator at the high school or college level, visit our Education Discount Policy page to establish an education account number.

If you are placing an order, you may proceed with your order; the account price will
be applied if it is lower than the
list price. If the problem persists, please call customer service at or send an
email to

For more than 15 years, Bio-Rad has made science education a major priority. To support this effort, the company has implemented a discount policy that allows high school and college teaching laboratories to purchase kits, instruments, reagents, and other equipment at preferred prices.

How do I apply for the education discount?

If you are an educator at the high school or college level, visit our Education Discount Policy page to establish an education account number.

If you are placing an order, you may proceed with your order; the account price will
be applied if it is lower than the
list price. If the problem persists, please call customer service at or send an
email to

For more than 15 years, Bio-Rad has made science education a major priority. To support this effort, the company has implemented a discount policy that allows high school and college teaching laboratories to purchase kits, instruments, reagents, and other equipment at preferred prices.

How do I apply for the education discount?

If you are an educator at the high school or college level, visit our Education Discount Policy page to establish an education account number.

For more than 15 years, Bio-Rad has made science education a major priority. To support this effort, the company has implemented a discount policy that allows high school and college teaching laboratories to purchase kits, instruments, reagents, and other equipment at preferred prices.

How do I apply for the education discount?

If you are an educator at the high school or college level, visit our Education Discount Policy page to establish an education account number.

For more than 15 years, Bio-Rad has made science education a major priority. To support this effort, the company has implemented a discount policy that allows high school and college teaching laboratories to purchase kits, instruments, reagents, and other equipment at preferred prices.

How do I apply for the education discount?

If you are an educator at the high school or college level, visit our Education Discount Policy page to establish an education account number.

For more than 15 years, Bio-Rad has made science education a major priority. To support this effort, the company has implemented a discount policy that allows high school and college teaching laboratories to purchase kits, instruments, reagents, and other equipment at preferred prices.

How do I apply for the education discount?

If you are an educator at the high school or college level, visit our Education Discount Policy page to establish an education account number.

For more than 15 years, Bio-Rad has made science education a major priority. To support this effort, the company has implemented a discount policy that allows high school and college teaching laboratories to purchase kits, instruments, reagents, and other equipment at preferred prices.

How do I apply for the education discount?

If you are an educator at the high school or college level, visit our Education Discount Policy page to establish an education account number.

For more than 15 years, Bio-Rad has made science education a major priority. To support this effort, the company has implemented a discount policy that allows high school and college teaching laboratories to purchase kits, instruments, reagents, and other equipment at preferred prices.

How do I apply for the education discount?

If you are an educator at the high school or college level, visit our Education Discount Policy page to establish an education account number.

For more than 15 years, Bio-Rad has made science education a major priority. To support this effort, the company has implemented a discount policy that allows high school and college teaching laboratories to purchase kits, instruments, reagents, and other equipment at preferred prices.

How do I apply for the education discount?

If you are an educator at the high school or college level, visit our Education Discount Policy page to establish an education account number.

For more than 15 years, Bio-Rad has made science education a major priority. To support this effort, the company has implemented a discount policy that allows high school and college teaching laboratories to purchase kits, instruments, reagents, and other equipment at preferred prices.

How do I apply for the education discount?

If you are an educator at the high school or college level, visit our Education Discount Policy page to establish an education account number.

For more than 15 years, Bio-Rad has made science education a major priority. To support this effort, the company has implemented a discount policy that allows high school and college teaching laboratories to purchase kits, instruments, reagents, and other equipment at preferred prices.

How do I apply for the education discount?

If you are an educator at the high school or college level, visit our Education Discount Policy page to establish an education account number.

I cannot find the Certificate of Analysis I am looking for. Help!

When using our online Certificate of Analysis search tool, keep the following in mind:

Make sure you entered the correct catalog number and lot/control number in the search fields

If you have a kit, try looking up the Certificate of Analysis using the kit information as well as the information for the individual components

The Certificate of Analysis that you are looking for may not be available via the website. In that case, you can contact your Bio-Rad representative or use the Request Form

If you cannot find the Certificate of Analysis you are looking for, please Contact Us.

Where can I find the catalog number, SKU number, or product number?

The catalog number, SKU number, or product number is printed on your product label. See the sample label below for the location of this information.

Where can I find the lot or control number?

The lot number or control number (one or the other, not both) is printed on your product label. See the sample label below for the location of this information.

Why are Certificates of Analysis not on the Documents tab?

Certificates of Analysis are associated not only with a product, but also with a specific lot of that product. For a given product, there may be several Certificates of Analysis, especially if it is an older product line and has had several lots produced over the years. Using the Certificate of Analysis search tool, you can enter the catalog number and lot/control number for the specific product you have on hand and download the exact Certificate of Analysis you need.

I have a batch number, not a lot/control number. How do I find the Certificate of Analysis for my item?

You can use the batch number in place of the lot/control number. Use the Certificate of Analysis search tool, entering the catalog number as usual and the batch number where the lot/control number would go.

Can I get a Certificate of Analysis even if my item is expired?

Yes. While we do periodically remove Certificates of Analysis for site maintenance purposes, we typically keep them available well beyond a product's expiration date.

Why does it say "Product Name Not Found" for a Certificate of Analysis listed in the search results?

There are Certificates of Analysis that correspond to products that are either discontinued or simply not available on the website. In these situations, the Certificate of Analysis is available for download, but other product details, such as the product name, are not.

Why does it say "Not Available" for a Certificate of Analysis listed in the search results?

In this case, you have entered a valid catalog number and lot/control number and we have located the Certificate of Analysis. However, for some reason, the actual file itself is unavailable.

Please use the Request Form here or contact your local Bio-Rad Representative so that we can send you the Certificate of Analysis.

Your subscription information already exists, we will send you an email with specific instructions to manage your existing subscription profile.

To receive the latest news, promotions, and more, sign up for Bio-Rad updates by entering your email address below. You can elect to receive only the types of Bio-Rad communications that are of interest to you..